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Edition 04/14

Article and Compact news

Our AERZEN customer journal "AERZEN com.press" will provide you with detailed information at regular intervals about our company, our products and application solutions.

Article

Berliner Luft (The Berlin Air)

AERZEN TURBO convinces with the new concept for oxygen introduction at Wansdorf sewage plant

In the mechanical and biological sewage treatment plant at Wansdorf, near Berlin, an old Turbo blower was exchanged with an AERZEN product of the new series AT Turbo “Generation 5”. What started out as a test, has, based on the positive experiences that followed, now become an integral part of the plant.

Wansdorf sewage plant
In the Wansdorf sewage plant in the northwest of Berlin among others an AERZEN turbo blower type AT 400-0.8 ensures the required oxygen.
Initially, the AERZEN turbo blower was made available free of charge for a field test. One year later, it was taken over by the sewage plant.
sewage plant-Berlin

The company operating the Wansdorf sewage plant, which was completed in 1998, is a co-operation between Berliner Wasserbetriebe, four municipal authorities and a special-purpose association in Brandenburg. More than half of the waste water purified in Wansdorf comes from Brandenburg, and the rest comes from Berlin. The plant was designed for a population equivalent of 200,000.

As the waste water being purified is mainly communal, plus an additional quantity of industrial waste water, the volume of water being purified has a pollution load which corresponds to a population equivalent between 300,000 and 320,000. The maximum capacity of the sewage plant is 40,000 cubic metros of waste water every day.

Until then, the oxygen for the aeration basin had been generated by three turbo compressors, supplied by a company now owned by a German concern.

Practical experience provided the proof

However, in March 2013, permanent and costly maintenance and repairs led to an exchange of the old compressor for an AERZEN Turbo. “The old units were compressors with integrated inlet and outlet guide vanes”, explains Dipl.-Ing. Uwe Klauditz, an employee of Berliner Wasserbetriebe and technical operations manager
of Wansdorf sewage plant. “This required extensive technology and very special knowledge for maintenance. Accordingly, the costs for maintenance work and overhaul were high. We absolutely wanted to end this unsatisfactory situation.” So they decided to check with the Turbo blower made available by AERZEN, the suitability of the new Generation 5 series under practical conditions. It is a decision they did not regret, and it was the test that convinced them: “We immediately used the packaged unit via the integrated demand-dependent control in continuous operation. Following some subsequent improvements at the beginning of thetest phase, the result for us was so positive that after one year we decided to purchase the test unit”, says Klauditz.

AT Turbo for the base load

Currently, the new AERZEN turbo blower operates autonomously via its own control system; in future it is planned to be integrated as base load blower into the overriding, pressure dependent control system of the complete station. Then the two remaining units with demand-dependent capacity will cover the peak demand. Nowadays there are many good arguments for turbo blowers in biologically working large-scale sewage plants: the AERZEN compressor system works very reliably, offers high energy efficiency, distinguishes itself by high conveying volumes and offers sufficient maximum pressure of up to 1.0 bar. The new Aerzen AT-turbo blowers are driven by high-speed permanent magnetic motors (PM-motors) and may be adjusted via a frequency converter without additional mechanical adjusting devices infinitely variable between 40% and 100% to fluctuating air needs.

In the absolutely oil-free working units the only medium to be compressed in these units is the air that is used for the bearing of the shaft and for cooling the system. The new AT-series “Generation 5” made by AERZEN works with a corrosionresistant and robust impeller made of stainless steel. Its high strength makes reduced wall thicknesses possible, offers better aerodynamics and considerably improved efficiency.

The especially manufactured frequency converter also contributes to this improved efficiency. Due to permanent monitoring in case of unforeseen pressure fluctuations it avoids an uncontrolled shutdown of the machine to the surge limit.

Higher safety, lower costs

According to Managing Director Axel Swoboda, the new AERZEN turbo blower in Wansdorf makes a significant contribution to the legally conformant operation of the sewage plant - thanks to a stabilization of the stipulated inflow values of the purified waste water into the open water. The energy consumption of the blower station, by far the biggest energy consumer at Wansdorf sewage plant, cannot be recorded separately. But since the commissioning of the AERZEN unit the expenditure on energy for the entire sewage plant has reduced considerably compared with previous years.

Klauditz is sure that this positive development is mainly due to the high energy-efficiency of the new Aerzen Turbo blower. “Also, as far as energy costs are concerned, with AERZEN we are obviously on the safe side”, emphasizes Klauditz.

Therefore, based on their positive experiences, in case of further investments being made into oxygen generation, they will contact AERZEN again immediately.
 

Compact news

Energy efficiency is an important issue in South Africa

Electra Mining Africa in Johannesburg is the biggest industrial exhibition on the continent. 35,000 visitors attended the fair which took place from 15th to 19th September. AERZEN was represented by Airgas Compressors at a modern and attractive fair stand. Airgas presented - energy- efficient solutions - made by AERZEN - for air and gas conveying. In this context, consider our Delta Hybrid D12S with frequency converter. The increased pressure range, the low noise level and the functionality of the AERtronic Controller specially impressed visitors from the waste water industry. An interactive touchscreen with 3D animation illustrated the advantages of the energysaving Delta Hybrid. Due to uncertain supply and rising costs of electricity, energy efficiency is of growing importance in South Africa.

Clean air for Durango

With a total investment of EUR 1.6 million, the Mexican city of Durango is equipping its 18 years old sewage works with a new ventilation system. This is the first step in a large scale project for improving the air and consequently the quality of life, for people in more than 100 villages in the region as it rapidly develops. In addition to the unit, AERZEN México is providing two Turbo AT 400-0.8T which will make an important contribution - they are extremely energy efficient and low in maintenance making them unique in the whole of Latin America.

ATEX-compliant version of ASP oil demister

AERZEN SPECIAL PRODUCTS BV in the Netherlands has developed an ATEX-design of its oil demister. ATEX is the name of a European directive for devices and protection systems, used in potentially explosive atmospheres. The ATEXconformity, referring to gas and dust, has been tested and certified by DEKRA (a leading audit company in Europe). For the ATEX-design, several components of the standard oil demister were modified: Not only were the filter mats replaced with a more conductive stainless steel version, but due to the increased weight the entire drum was replaced as well. Furthermore, all the bolts were provided with special spacing collars.

Insights into AERZEN’s world

On the occasion of the company’s 150th anniversary, AERZEN hosted an Open Day on 20th September. The young, the old, relatives and friends of staff, partners of AERZEN and other guests interested in the company all came. The flow of visitors started in the morning and did not stop until late afternoon. All in all, 5,600 guests took the opportunity to experience an informative and exciting day with and at AERZEN. This was a significantly higher number of guests than came to the last such event in 2004.